Minnesota Gov. Tim Pawlenty announced on Tuesday that he is going to sue over President Obama's federal health-care law.

"The federal government is now requiring citizens under penalty of a fine to buy a good or a service, and we think that's an unprecedented overreach by the federal government into the lives of individual citizens," the Republican said.

Former Alaska Gov. Sarah Palin, who is weighing a GOP presidential run of her own, has used her Facebook page to put 20 House Democrats "in the cross-hairs."

The 20 districts targeted by Palin are all represented by a Democratic member of Congress who voted for Obama's health-care overhaul, even though they represent districts that were carried by McCain-Palin in 2008.

Pawlenty will either join the suit already being brought by 13 Republican state attorneys general or bring one himself, his spokesman said.

Pawlenty feels compelled to take this action himself, according to his spokesman, because the state's Democratic attorney general, Lori Swanson, rejected Pawlenty's request that she file a lawsuit on behalf of the state.

Echoing the view of the Obama administration and many legal experts, Swanson said a suit isn't warranted because the new requirement to purchase health insurance fits squarely within the federal government's authority to regulate interstate commerce.